I have situation which I can best describe as follow.

I have 2 sets A and B. Each sets contains few strings. I have to compare and find out approximately which string of set A matches with which string of set B. It's possible that some sttrings will go unmatched. Approximately means differing in letters by 1 to 3 characters. Each string length is max 10 characters. Sets A and B doesn't contain the same number of strings and number of strings in each set could go from 1 to 25.
In actual case these sets are merged and it is most likely that set B string comes after set A string. But that's not true always. To give u an example, I may have patterns like 1. ABAB or 2. ABBA or 3. ABB or 4. ABABAAB. If I get the scenes like AAB or ABB it may not be very clear as which pairs are matching and that's why I need string approximation.

Hope, I explained it properly, feel free to ask anything more.

Thanks,
Artist